Stabilise Bifrost CI job

The Bifrost CI job seems quite unstable, often failing while attempting
to reach the public epel package repositories. We shouldn't need to
install any packages when deploying the container - they should all have
been installed in the image already.

This change avoids running the scripts/env-setup.sh script, which is run
when the container image is built.

It also removes sourcing of /opt/stack/ansible/hacking/env-setup, which
is now just a stub.

Change-Id: I1786e5337a397cb7b427d6b87c21eaee600af170

ansible/roles/bifrost/tasks/bootstrap.yml

@@ -15,7 +15,7 @@
 - name: Bootstrap bifrost (this may take several minutes)
   command: >
      docker exec bifrost_deploy
-     bash -c '/bifrost/scripts/env-setup.sh && source /bifrost/env-vars
+     bash -c 'source /bifrost/env-vars
      && cp /etc/bifrost/rabbitmq-env.conf /etc/rabbitmq/rabbitmq-env.conf &&
      chown rabbitmq:rabbitmq /etc/rabbitmq/rabbitmq-env.conf &&
      ansible-playbook -vvvv -i /bifrost/playbooks/inventory/target

ansible/roles/bifrost/tasks/deploy-servers.yml

@@ -2,8 +2,7 @@
 - name: Enrolling physical servers with ironic
   command: >
      docker exec bifrost_deploy
-     bash -c 'source /bifrost/env-vars
-     && source /opt/stack/ansible/hacking/env-setup &&
+     bash -c 'source /bifrost/env-vars &&
      export BIFROST_INVENTORY_SOURCE=/etc/bifrost/servers.yml &&
      ansible-playbook -vvvv -i /bifrost/playbooks/inventory/bifrost_inventory.py
      /bifrost/playbooks/enroll-dynamic.yaml -e @/etc/bifrost/bifrost.yml'
@@ -11,8 +10,7 @@
 - name: Deploy physical servers with ironic
   command: >
      docker exec bifrost_deploy
-     bash -c 'source /bifrost/env-vars
-     && source /opt/stack/ansible/hacking/env-setup &&
+     bash -c 'source /bifrost/env-vars &&
      export BIFROST_INVENTORY_SOURCE=/etc/bifrost/servers.yml &&
      ansible-playbook -vvvv -i /bifrost/playbooks/inventory/bifrost_inventory.py
      /bifrost/playbooks/deploy-dynamic.yaml -e @/etc/bifrost/bifrost.yml'